The property was added so that we were able to set the main page
dynamically based on the feature switch value. This is no longer needed and
we can use the hardcoded constant as we did before.
[MAILPOET-4831]
MailPoet adds a link to the WooCommerce task list pointing to its own
welcome wizard. We want to track users that arrive to the MP wizard from
WooCommerce but at this point tracking is not enabled. So we store the
information in a setting, and send the tracking event to Mixpanel, if it
is enabled, after the user completes the wizard.
[MAILPOET-4814]
